Numerous liners or padding are employed in prosthetic and orthopedic systems, and serve as an interface between a corresponding prosthetic or orthopedic device and a limb.
By way of example, in the field of prosthetic devices, a liner sleeve is generally understood as a sleeve worn over a post-operative stump or limb that serves as the interface between the limb and a prosthesis or a prosthetic device, such as a hard socket. Liners are typically made of an air impermeable elastomer material, such as silicone. Liners may comprise a single layer or multiple layers, with different layers providing different benefits to the wearer.
Liners are used traditionally to cushion a post-operative stump or limb with respect to a prosthesis that is installed over the limb and coupled to the sleeve by a conventional locking mechanism. The thickness of the liner may be increased to provide additional cushioning between the limb and the prosthesis, thereby increasing comfort to the user.
In addition to providing cushioning, the liner also serves to protect the limb from irritation that might be caused by movement of the prosthesis against the limb. In the absence of a liner, the prosthesis will directly contact the skin. Any movement or slippage of the prosthesis at the interface with the limb will therefore result in friction between the prosthesis and limb and, consequently, irritation to the limb. Presence of the liner between the limb and the prosthesis eliminates this problem by serving as a protective barrier between the limb and the prosthesis. In other words, movement at the interface with the limb will be borne by the liner and not the limb.
Of course, in order for the liner to protect the limb from irritation caused by movement of the prosthesis at the interface between the prosthesis and the limb, the liner preferably does not slip on the limb. That is to say, if the liner is capable of slipping on the limb, then the limb may become irritated by the friction caused by the liner rubbing against the skin of the limb.
Traditionally, liners have addressed this issue by utilizing a liner having a tacky surface for the surface that comes into direct contact with the skin of the limb. The tacky inner surface of the liner ensures the liner does not slip or rub against the skin of the limb. The liner stays firmly in place against the limb, even when external forces such as movement of the prosthesis against the external surface of the liner are acting on the liner.
The tacky inner surface of a liner does not always prevent slippage of the liner against the limb. Specifically, when the liner is made from a non-absorbent elastomer material, perspiration build-up in the liner tends to cause the liner to lose suspension. The equal pressure applied to the limb by the liner results in a thin film of perspiration forming and distributing throughout the liner. The thin film of perspiration forms an essentially frictionless gap between the limb and the liner, thus allowing the liner to easily slide on the limb. With no means to escape, the thin film of perspiration builds up between the limb and slippage of the liner is more likely to occur.
Liners find a variety of applications also in orthopedic devices for providing an interface to the limb. Such liners may be used alone in reinforcing a limb, or may include reinforcing elements or be used in combination with braces for a variety of anatomical portions.
It is therefore one of the objects of the embodiments described herein to create an improved liner that effectively manages perspiration formed by a limb, prevents slippage of the liner on the limb, and further provide suitable cushioning for the limb. Such a liner can be used in a variety of applications for both prosthetic and orthopedic systems in combination with prosthetic and orthopedic devices.